[TowerTalk] Resonance of loaded Parasitic Elements

[Maurizio Panicara]

A full size quad reflector and a shortened yagi element won't behave the
same likewise they won't have the same fed point impedance. The same rule
that worked once with a peculiar case won't necessary work on another
antenna type.
Shortenings and lenghening are enough ruled by own design preferences (fed,
gain, F/B, BW) and by spacing if that is planned to produce a decent F/B,
the weak point in a 2 element parasitic yagi array.

73,
Mauri I4JMY


> You will find the driven element will be slightly shorter than free-
> space resonance, about 5%, for minimum reactance.
>
> I just had a friend tune a quad by installing only the reflector. He
> fed the reflector like a dipole, and set it for resonance on the lowest
> frequency he planned on using (using an exact 1/2 wl of coax to
> the meter). He then closed the loop, and added the driven element.
>
> He didn't have to touch a thing, it came out just as predicted.
> 73, Tom W8JI
> W8JI@contesting.com
>
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List Sponsored by AN Wireless:  AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 96 feet for under $1500!!  http://www.anwireless.com

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